Lens de-blocking device



May 28, 1963 J. M. SUDDARTH LENS nmswcxmc DEVICE Filed Sept. 17, 1 962JACK M. SUDDARTH United States Patent 3,091,062 LENS DE-BLOKING DEVICEJack M. Suddarth, Muskogee, Okla, assignor to Coburu ManufacturingCompany, Inc., Muskogee, Okla, a corporation of Oklahoma Filed Sept. 17,1962, Ser. No. 224,033 7 Claims. (Cl. 51-277) This invention relates toan apparatus for removing a chucking block from a lens blank after thelens blank has been through an abrading process. More specifically, theinvention relates to a hand operated device for efficiently removing ametallic block from the lens surface through the use of very slightpressure and without the use of chemicals.

In the process of generating a lens surface, or in beveling itsperiphery with conventional grinding and abrading equipment known to theart, it is necessary to attach a chucking block to one surface of thelens blank in order that it may be firmly held and accurately positionedwith respect to the cutting tools. The fragile nature of the lens blankmakes direct chucking undesirable. There are various methods ofattaching the block to the lens and the disclosed embodiment isspecifically concerned with removing circular blocks, which are securedto the surface of a lens via a low melting point alloy, from the convexsurface of a lens blank.

An objective of this invention is to provide a device which mechanicallyremoves the chucking block from the lens with greatly reduced incidenceof lens breakage.

A further objective of the invention is to provide an apparatus forremoving a chucking block from a lens and which apparatus is inexpensivein its manufacture and rugged and simple in its operation.

A further objective of this invention is to provide a lens de-blockingdevice in which the lens surface is engaged by a ring-like member suchthat an operator may cause a progressive separating force from one sideof the lens to the other.

A still further objective of the invention is to provide means wherebythe above-mentioned progressive line of force may commence along anyselected diameter of the lens.

A further objective of the invention is to provide an apparatus of thecharacter described in which the elements are so constructed that Wearplates are conveniently mounted and are readily replaced to increase thelife of the device itself.

These and other important objectives and advantages of the inventionwill hereinafter become more fully apparent from the followingdescription of the drawings, illustrating a presently preferredembodiment of the invention, and wherein:

FIGURE 1 is a side elevation of a lens blank having a chucking blocksecured thereto;

FIGURE 2 is an exploded perspective of the principal elements of thisinvention;

FIGURE 3 is a partial side elevation showing the assembled elements justprior to inserting the lens block assembly into the apparatus; and

FIGURE 4 is a cross-sectional view showing the elements in their lensde-blocking position.

Referring now more particularly to the drawings wherein like numeralsindicate like parts, the numeral designates the presently preferredembodiment of this invention. The embodiment is provided with a base 12from which a cylindrical standard 14 upwardly extends.

The standard consists of an annular wall 14, and is 3,991,062 PatentedMay 28, 1963 "ice bottomed at 18 by a portion of base 12. A spindle 20is received in the standard 14 and is fixedly secured thereto by anAllen screw or the like 22 through the threaded apertures 24 and 26, ofthe standard and spindle respectively. The cylindrical spindle istapered about its upper end at 28. The spindle is centrally bored at 30to receive a coil spring 32, and about the upper surface thereof, isprovided .with an upwardly extending annular flange 34 which defines ablock receiving pocket or seat 36. The inner periphery 38 of Wall 36 isvertical, and the outer periphery is defined by the previously mentionedtaper 28. The flange 34 is terminated by the annular upper edge 39.

Between the spindle 20 and the wall 16 a ledge 40 is formed. Anexpanding ring assembly 42 is adapted to slide over the spindle 20 andbe rotatably supported on ledge 40. The assembly 42 is comprised of afirst lower ring 46 and a second upper ring 48 of substantially the samedimensions.

The lower ring is formed with an outwardly and upwardly extending arm 50which is apertured at 52. Formed along the periphery of upper ring 48,adjacent to arm 50, is a bifurcated arm 54 which is apertured at 56 and56'. Arms 50 and 54, along with pin 58, form a pivotal connectionbetween the rings.

Diametrically opposed to the arm 50, the lower ring is provided with anoutwardly and upwardly extending arm 60 which is apertured at 62.Pivotally secured to arm 60 is an operating lever 64 by way of a pin 66.Immediately above the arm 60, and spaced therefromQa bearing lug 68protrudes from upper ring 48. A wear plate 70 is secured to theunderside of lug 68 via the screw 72.

The operating lever is comprised of a handle 74, a fulcrum recessthrough which pin 66 extends, and a forwardly extending boss 76 which isreceived in the space between the lug 68 and arm 60. A screw 78, hav-.ing a wear plate head 80, is secured to the boss in mating relationshipwith wear plate 70.

A pair of biasing springs 82 and 84 extend between the upper and lowerrings and maintain the wear plates and 78 in engagement with oneanother. The springs normally bias the rings 46 and 48 toward each otherto a substantially edge-to-edge relationship. A screw 85 extends througharm 60 below the pivot point, and will adjustably limit the pivotingmovement of the operating lever by engaging a side wall of recess'65.The upper ring is counterbore at 86 to receive an annular fiber member88. As will become more apparent hereinafter, the fiber member providesa relatively non-abrasive contact surface between the apparatus and thelens blank.

In FIG. 1 there is shown a lens blank L secured to a circular block B bythe previously mentioned low melting point alloy A. It is commonpractice to coat the convex side of the lens with a quick dry plasticprior to applying the alloy. This coating protects the lens surface andmakes block removal an easier operation.

The assembled elements are shown in cross-sectional elevation in FIG. 3,just prior to the insertion of the workpiece. It should be noted that inthe assembled arrangement, the upper edge of fiber ring 88 extendsslightly vabove the upper edge 39 of the seat and the coil spring ring88 is spaced from pivot pin 58, the top edge of the fiber ring, which isin annular engagement with the lens, exerts a continuous progressiveforce from left to right, as viewed in FIG. 4. This progressive forcealong two semi-circular arcuate lines provides an annular line of forceabout the lens blank which greatly reduces the amount of breakageencountered in other lens de-blocking devices. In those instances wherean operator is confronted with a particularly tight bind between thelens and block, the operator can rotate the ring assembly 42 about thespindle 20, while repeatedly depressing handle 64, until a point aboutthe seal is found that is weak enough to break.

Since, the block itself cannot tilt, because of the close tolerancesbetween it and the inner periphery of the seat, no other apparatus isrequired to vertically secure it with respect to the lens blank. Whenthe upper ring applies the pressure to the lower surface of the lens thelens block, of course, due to a tendency to tilt, will bind itselfslightly within flae seat. A slight tap on the block will normally breakthe bind and along with the spring the block is easily removable fromthe seat, and the device is ready to receive another workpiece.

In a general manner, while there has been disclosed in theabove-description, what is deemed to be the most practical and efiicientembodiment of the invention, it should be well understood that theinvention is not limited to such an embodiment as there might be changesmade in the arrangement, disposition and form of the parts withoutdeparting from the principle of the present invention as comprehendedwithinthe scope of the accompanying claims. 7

I claim:

1. A device for removing a block from the Surface of a lens-blankcomprising a base, a standard of lesser crosssection than said baseextending upwardly therefrom and defining a step with said base, anupwardly extending flange about the top of said standard defining a seathaving an inner wall configuration closely approximating the outerperiphery of said block, a base ring rotatably received aboutsaidstandard and support by said ledge, an upper ring about said standardpivotally securedto said base ring, said upper ring having a firstposition wherein its upper edge is parallel to and slightly above theupper edge of-said flange and is in engagement with the surface of saidlens when said block is inserted in said seat, and means to tilt saidupper ring from said base ring whereby said lens 'is tilted away fromsaid block.

2. A device for removing a block from the surface of a lens blankcomprising a base, a standard of lesser crosssection than said baseextending upwardly therefrom and defining a step'with said base, anupwardly extending flange about the top of said standard defining a seathaving an inner wall configuration closely approximating the outerperiphery of said block, a first ring rotatably received about saidstandard and support by said ledge, and \a second ring about saidstandard pivotally secured to said base ring, said second ring having afirst position wherein its upper edge is parallel to and extendsslightly above the upper edge of said flange and in engagement with thesurface of said lens when said block is inserted in said seat, and meansto tilt said first ring upwardly from said base ring such that said lensis tilted away from said block by a pressure exerted by said secondedge. V

3. A device for removing a block from the surf-ace of a lens blankcomprising, a base, a standard of lesser crosssection than said baseextending upwardly therefrom and defining a step with said base, anupwardly extending flange about the top of said standard defining a seathaving a vertical inner wall configuration closely approximating theouter periphery of said block and an inwardly directed taper along theouter wall thereof, a lower ring rotatably received about said standardand supported by said ledge, an upper ring about said taper andpivotally secured to said base ring, said upper ring having a firstposition wherein its upper edge is parallel to and extends slightlyabove the upper edge of said flange and is in engagement with thesurface of said lens when said block is inserted in said seat, and meansto tilt said upper ring from said base ringwhereby said lens is tiltedaway from said block.

7 4. A device for removing a block from the surface of a lens blankcomprising a base, a standard of lesser crosssection than said baseextending upwardly therefrom and defining a step with said base, anupwardly extending flange about the top of said standard defining a seathaving a vertical inner wall configuration closely approximating theouter periphery of said block and an inwardly directed taper along theouter wall thereof, a lower ring rotatably received about said standardand supported by said ledge, anupper ring about said taper and pivotallysecured to said base ring, a coil spring in said seat, said upper ringhaving a first position wherein its upper edge is parallel to andextends sli htly above the upper edge of said flange and is inengagement with the surface of said lens when said block is inserted insaid pocket, and means to tilt said upper ring from said base ring to asecond position whereby said block is unable to tilt in said seat, saidlens is tiltable away from said block by said lever, and said coilspring aids in removing said block from said seat after the lens isseparated from said block.

5. A device for removing a block from the surface of a lens blankcomprising a base, a standard of lesser crosssection than said baseextending upwardly therefrom and defining a step with said base, anupwardly extending fiange about the top of said standard defining a seathaving an inner wall configuration closely approximating the outerperiphery of said block," a lower ring rotatably re-- ceived about saidstandard and supported by said ledge, an upper ring about said standard,means pivotally securing said lower ring to said ring at a first pointalong their peripheries, said upper ring having a first position whereinits upper edge is parallel to and extends slightly above the upper edgeof said flange and is in engagement with the surface of said lens whensaid block is inserted in said seat, an operating lever pivotallyattached to said lower ring at a second point diametrically opposed tosaid first point, one end of said lever in contact with the lower edgeof said upper ring whereby when the other end of said lever isdepressed, said upper ring and 'said lens are tilted away from saidblock.

6. A device for removing a block from the surface of a lens blankcomprising a base, -a standard extending outwardly from said 'base anddefining a step therewith, a flange about the outer end of said standarddefining a seat having an inner wall configuration closely approximatingthe outer periphery of said block, a first ring rotatably received aboutsaid standard and supported by said ledge, a second ring about saidstandard pivotally secured to said first ring, said second ring having afirst position wherein a first edge is prarallel to and slightly abovethe edge of said flange and is in engagement with the surface of saidlens when said block is inserted in said seat, and means to tilt saidfirst ring from said second ring whereby said lens is tilted away fromsaid block. a g

7. An apparatus for removing a sealed chucking block from the convexsurface of a lens blank comprising upper and lower coaxial annular ringscircumscribing said block,

said upper ring in annular engagement with said convex surface of saidblank, means rotatably mounting rings with zrespect to said block, ahinge pivotally connecting said upper ring to said lower ring, a seatrigidly securing said block against a. tilting movement, and secondmeans to pivot said upper n'ng with respect to said block about saidhinge and against said lens.

References Cited in the file of this patent UNITED STATES PATENTS Pellowet a1. Dec. 1, 1914 Bugbee Oct. 22, 1918 Hill June 19, 1923 Long et al.Oct. 30, 1951 Allen et :al. Mar. 31, 1939

7. AN APPARATUS FOR REMOVING A SEALED CHUCKING BLOCK FROM THE CONVEXSURFACE OF A LENS BLANK COMPRISING UPPER AND LOWER COAXIAL ANNULAR RINGSCIRCUMSCRIBING SAID BLOCK, SAID UPPER RING IN ANNULAR ENGAGEMENT WITHSAID CONVEX SURFACE OF SAID BLANK, MEANS ROTATABLY MOUNTING RINGS WITHRESPECT TO SAID BLOCK, A HINGE PIVOTALLY CONNECTING SAID UPPER RING TOSAID LOWER RING, A SEAT RIGIDLY SECUR-